Arc’teryx Alpha FL Jacket

Luke Koppa reviews the Arc'teryx Alpha FL Jacket for Blister Gear Review.
Arc’teryx Alpha FL Jacket

Arc’teryx Alpha FL Jacket

Size Tested: Medium

Stated Weight: 326 g

Blister’s Measured Weight: 309 g

Front Zipper Length (Size M): 69.2 cm

Stated Features:

  • Micro-seam allowance (1.6 mm) reduces bulk and weight
  • GORE-TEX® Pro three-layer construction
  • Tiny GORE® seam tape
  • Anatomical shaping for fit and comfort
  • Articulated elbows
  • e3D Ergonomic 3-Dimensional patterning for enhanced comfort and mobility
  • No-lift gusseted underarms
  • Trim fit for enhanced breathability
  • Helmet compatible StormHood™
  • Laminated brim
  • Externally accessed hood drawcords
  • WaterTight™ Vislon front zip
  • Laminated die-cut Velcro® cuff adjusters reduce bulk, and won’t catch or tear off
  • Drop back hem
  • Adjustable hem drawcord
  • Two-piece harness Hemlock™ inserts fold betted and keep jacket in position under harness
  • Includes stuff sack with webbing loop to clip to a harness


  • Chest pocket with laminated zip

MSRP: $399 USD

Reviewer: 5’8″, 150 lbs

Test Locations: Rocky Mountain National Park & Fort Collins, CO; Milwaukee & Eagle River, WI;

Days Tested: 50+


The Arc’teryx Alpha FL’s name is indicative of its intended use – “Alpha” refers to Arc’teryx’s climbing-oriented Alpha series, and the “FL” indicates the jacket’s “Fast and Light” focus.

The Alpha FL sits between the Alpha AR (All-Around) and SL (Superlight), and although it is intended for a niche use and has a correspondingly particular featureset, I have found the Alpha FL to be a solid go-to shell for everything from ski mountaineering to bike commuting.


One of the best attributes of every Arc’teryx piece I’ve used is the fit. A quick inspection of the seams reveals an intricate pattern designed with movement in mind, and the Alpha FL is no exception. Arc’teryx labels the Alpha FL’s fit as Trim, while utilizing the brand’s e3D patterning, which Arc’teryx describes as allowing “for enhanced mobility for sport-specific activities in challenging environments.”

Unlike some alpine shells which seem to just be smaller versions of their snowsport counterparts, the Alpha FL’s fit is slim through the torso while leaving room in the sleeves and shoulders for freedom of movement. The Alpha FL fits nicely over my Patagonia Nano Puff Pullover as well as my Arc’teryx Atom LT, and there isn’t much extra, bulky fabric when worn with a midlayer – which is what I prefer in a climbing shell.

Luke Koppa reviews the Arc'teryx Alpha FL Jacket for Blister Gear Review.
Luke Koppa in the Arc’teryx Alpha FL Jacket.

The jacket has a noticeably longer drop hem (about 9.5 cm lower than the front), which comes in handy when taking a seat in snow or while biking. The sleeve and shoulder articulation works very well, and I never felt that my range of motion was limited by the shell while climbing.


The defining feature of the Alpha FL is its fabric: Gore-Tex Pro with a 40-denier nylon face fabric. You can check out our “Outerwear 101” and “201” articles for more details on waterproof/breathable membranes, but Gore describes their Pro fabric as “engineered with added durability to withstand abrasion in rugged environments while protecting against extreme and unpredictable conditions with frequent work-rest cycles.”

During my extended time in the Alpha FL, I have come away impressed with the Gore Pro membrane. I’ve worn the jacket in everything from wind-driven sleet to extended downpours while backpacking and have never had any water penetrate the fabric.

The DWR has worked well during use, although the shoulders did wet out in situations where I was in heavy rain for hours. When I noticed the DWR failing faster than usual, I washed and tumble dried the jacket on low, which nicely revived the water repellency. In addition to routine washing and drying, I’ve re-treated my FL once with Nikwax during my 2+ years with it, which helped revive the DWR finish slightly more than a regular wash/dry cycle.


The Alpha FL breathes fairly well. It is certainly more breathable than traditional Gore-Tex as well and the older version / previous iteration of Gore Pro. I have also found it to be more breathable than the 2.5-layer membranes in both the Patagonia Torrentshell and Salomon Bonatti. However, the membrane is not air-permeable, and still requires a buildup of heat and moisture to start working.

Even though Gore describes their Pro membrane as being suited for activities with frequent work-rest cycles, this is not where I think the membrane excels. During extended, low-output activities like winter bike commuting and CO shoulder-season backpacking, the membrane was able to keep up. However, during higher-output periods (like hiking up early season ski lines) I noticed significant heat and moisture buildup inside the shell.

If my activities for the day require high exertion and poor weather is doubtful, I prefer to use a softshell like the old Patagonia Simple Guide jacket. Despite the recent advances in waterproof/breathable technology, fabrics with membranes still pale in comparison to those without when it comes to breathability. However, if there’s a good chance that I’ll be encountering a lot of precipitation that day, I will still bring the Alpha FL due to its reliable waterproofing and decent breathability.

Pockets and Features

The Alpha FL’s featureset matches its Fast and Light design; it has only one zippered chest pocket that sits slightly above the center of the jacket. The location of the pocket threw me off at first, as most jackets’ chest pockets are higher, but I have found that the pocket’s lower position allows the contents to sit more parallel to my torso instead of sitting atop my chest, which often happens with the Patagonia Houdini. Another benefit of the lower position is that you get full access to the zipper when wearing a pack with a sternum strap, which isn’t the case with the Houdini or Bonatti.

Luke Koppa reviews the Arc'teryx Alpha FL Jacket for Blister Gear Review.
Luke Koppa in the Arc’teryx Alpha FL Jacket.

The pocket is fairly large, and fits a pair of winter climbing gloves or a few bars. The jacket is not designed to stuff into the pocket, and instead includes a separate stuff sack that I rarely use. Although I would prefer to be able to stuff the jacket in its own pocket, I have not found this to be an issue, as I often just roll my jackets into their hoods to decrease wear on the fabric.

Some people may be worried by the Alpha FL’s lack of additional pockets or pit zips. During my time with the Alpha FL, there have been very few instances where I wished for more features. The full-length main zipper provides ample ventilation when needed, and the pocket fits most of my essentials (phone, wallet, bars). There have been a few times when I wished for pit zips, but these were all during hot and rainy days where any waterproof/breathable shell would struggle, pit zips or not.

During the few times I’ve used the Alpha FL ski touring, the lack of pockets for skins was inconvenient but unsurprising given the jacket’s intended use. The Alpha FL’s lack of handwarmer pockets should be noted, but I rarely use any of my shell’s handwarmer pockets since the thin material provides little to no warmth.

Beyond the pocket, the Alpha FL utilizes Arc’teryx’s “Hemlock” insert, which is a foam band embedded in the hem intended to keep the shell from rising above a harness. Unfortunately, my jacket did not come with the aforementioned foam, so I can not attest to its effectiveness. I’m sure Arc’teryx would have happily replaced the insert, as I have always had extraordinary experiences with their customer service department. However, I simply have never had many issues with my jackets rising above my harness, especially those like the Alpha FL that have dropped hems.

Arc’teryx has chosen to use a YKK Aquaguard Vislon water resistant zipper for the main zip of the Alpha FL, which is a major step up from traditional PU coated zippers like the one used on the chest pocket. The main zip is much easier to use than previous water resistant zippers, and can usually be coaxed into moving while using one hand.

A Velcro closure secures the cuffs. The Velcro Arc’teryx has chosen is very grippy and durable, and I have had no issues with performance. The cuff opening is 12” in circumference and is definitely smaller than that of my Arc’teryx Sabre jacket, but works well over low-profile gloves like the Mountain Hardwear Hydra Pro and Hestra Leather Fall Line. I was able to coax the cuffs over my Black Diamond Mercury Mitts, although this was difficult and mostly just a test, as gauntlet style mittens are not intended for this use.

NEXT: Hood, Durability, Etc.

10 comments on “Arc’teryx Alpha FL Jacket”

  1. Hi Luke,

    Thank you for your extensive review. I have to say that it is one of the best ones I have read so far.
    I saw that you mention that you layer this with the Atom LT. About the sizing, are they both same size or do you have the Alpha on a bigger size than the Atom?
    I’m about to buy an Alpha in XS, as that’s the size I have for the Atom but as I can’t find a store to try it I’m not 100% sure what to do.


    • Hi Filipe,

      Glad you enjoyed the review! I have both the Alpha FL and Atom LT in a size medium and am happy with both in that size. I like the fit of both when worn together (good range of movement but not too much excess space), but I wouldn’t wear anything bulkier than the Atom under the Alpha FL, as it is a pretty slim fit compared to most other shells.

      Hope this helps, and let me know if you have any other questions!


  2. Hi Luke,

    I am 5’7 145 lbs, planning to buy the Alpha FL for mountain hiking and might possibly use as a shell for winter time also. Only other piece of Arcteryx I own is a Squamish Hoody in XS and it fits really well with just a tee under. Not sure if I should buy the Alpha FL in S or XS as I also plan to layer beneath it? Would love to hear some advice.



    • Hi Darius,

      Thanks for reaching out. I haven’t had the chance to use the Squamish Hoody, but Arc’teryx states that the Squamish features their “athletic” fit which is supposed to be very similar to the Alpha FL’s “Trim” fit. So, if you are comfortable with the Squamish in just a T-shirt, I’d recommend sizing up to a size Small for the Alpha FL if you’re considering layering more than a T-shirt underneath. Although it’s patterned so that you can freely move your arms, the Alpha FL doesn’t have a whole lot of volume to it, and the thickest insulator I find myself layering underneath is a 60 g synthetic midlayer like the Arc’teryx Atom LT or Patagonia Nano Puff Pullover. Hope this helps, and let me know if you have any other questions.



    • As far as I know, the vast majority of Arc’teryx’s current products are made in Asia. I think some of their “Veilance” and “Leaf” collections are made in Canada, and also all of their prototypes, but all of the Arc’teryx products I’ve used in the past ~5 years have been made overseas (including the Alpha FL & Atom LT). With all that said, Arc’teryx is still one of our main reference points when it comes to well-constructed apparel.

  3. Hi, don’t have the opportunity to go to try on a physical jacket so I was hoping to get your opinion. I was interested in skiing and I was hoping to get a lightweight shell with not a trim fit. If I purchased the rho lt base layer with an small Atom ar midlayer, do you think that an small alpha fl would be big enough to layer with those pieces? I am a really skinny 6 ft/150lb guy. Thanks for your help!

  4. Sorry, meant to say I was looking for a trim fit. Also, what kind of weather would that three layer combination keep me warm in. Apologies, but I am not a frequent skier, so I am new to the three layer system.

  5. Any idea how the Arc’teryx Alpha FL Jacket would fit with Sabre AR Snow Pants. Just bought the jacket and wonder what the best fit would be. Some reviews suggest the jacket is cut quite high, I wonder if t
    the overlap will be enough?

    • Hmm, I think you’d be alright in terms of coverage, though it would be a bit of an odd look since the Alpha FL is so much slimmer than the Sabre AR pants. If you’d want a very light, Gore Pro jacket to match with the Sabre pant, the old Rush LT would be a great pick (if you can find one), or the Sabre LT / regular Rush. But if you mostly just want a very lightweight, minimal shell, I do think the Alpha FL offers just enough coverage, particularly in the back due to its notable drop-tail hem.

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